Process of preparing an adsorbent for oils



Aug' 16 1927 w. D. RIAL' ET AL PROCESS 0F BREPARNG AN ADSORBENT FOR OILS Original Filed Sept. 8, 1925 E Dl ,um um Bm. h N

9N VILLES Patented Aug. 16, 1927.

.UNITED lSTATES PATENT DFFICE.

WBT i). BILL AND MELE W. GARD, l' WILMINGTON, CALIIOBI'IA.

PROCESOI' PBEPABING AN .ADSOBBENT FIOR 0118.

flnal application med September This invention relates to a material for use in treating hydrocarbon oils of the petroleum or vegetable class for purposes of purification by adsorption, filtration or bleach- 6 ing and it has particular reference to an earthy material and to a method of producin the same for the desired uses in the o1l in ustry, this application being a dlvision of our (zo-pending application for patent 10 filed September 8,

The invention relates chiey to the treatment of clays and clayy materials and earths generally designated as colloidal claIy7 and hydrosilicate that may find use for li tering and otherwise treating oils, such materials comprising the usual clays at present employed in the art, diatomaceous earths, montmorillonite, and others. The treatment of these clays forming the subject of thls invention is to provide, at small cost of time, labor and apparatus, aclayey material with an slkali'content for the purpose of treating oils to obtain the eect of the alkali upon them and subject them further to the filtering, bleaching or other action of the clay, the prime object of the invention be1ng to provide a simple method by which these earthy materials may be made ready for use economically, and continuously without waste and which will eliminate the expensive systems at present in vogue. Y

A further object of the invention is to provide a method of treating clays and kindred earths, as a counterpart of an oil treating system involving the use of clays, in which the treated clays may be recovered 'for further use in the same system.

A further object of the invention is to provide a simple method of treating clays and kindred materials in which the expensive drying and other equipment, needed at present in the preparation of clayey material is eliminated, in which the clayey material may be treatedwith an alkali-treated oil similar to the oil which the clay is to treat, thereby avoiding additional cost and to provide a simple system in which the clay material may be re-used continuously until its effect upon the oil treated is exhausted.-

Other objects will appear from the specification following in connection with the accompanying drawing which is illustrative of a system in which the various steps of the process may be executed, the view dis- 1925, Serial Number s, ma, serial m. nabo?. mvma and um nppnmm ma prix as, ma -serm m. 104,540.

closing a diagrammatic lan of interrelated, co-operative apparatus or effecting the purposes of this invention.

In the practice of this invention, clay or clayey materials, are treated by commingling with them an oil, reviously treated with anv alkali whereby t e alkali content of the oil is absorbed by the clay, and this method we have found preferable to a direct mixin with the clay of the alkali because the alkali, under the conditions of vigorous agitation with the oil is intimately mixed and dispersed throughout the oil body, and hence is the more readily absorbed by the clay when in such disrupted condition that is, in a condition inwhich the alkali 1s broken up into fine particles. We have found that the clay thus treated will adsorb, to the point of saturation of the clay, the alkali disseminated through the oil, and that also a small proportion of the oil will be adsorbed by the clay, and that the undesirable content of oil may be readily discharged or expelled from the clay without interfering with the adsorbed alkali cont-ent of the clay, except that proportion of alkali` which is 1n excess of saturation of the clay. The removal of the adsorbed oil, we have found, is best accomplished by centrifugal force which leaves the clay practically free of oil. The clay thus treated is then ready for imme- Vdiate use in treating oils for any of the purposes for which clays are used, and the use of the clays treated, may be continuous until exhaustion of the alkali strength in the clay and impairment of the clay, in respect of its adsorptive qualities as well of its bleaching and filtering properties, has occurred. It will be obvious that the clay thus treated may be used immediately or kept for future use, but it is more economical continuously to make and use the clay until unfit for further use with the oil treated, While the clay is spent in treating certain oils, it is still available for further use in treating other oils.

The method as outlined, of treating clays for use in treating oils, in point of economy, ease of control, and consumption of labor and material, is superior toan of the methods, heretofore used, and in ad ition to yield- While any'of the available clays may be used for the purposes herein set out, and it will be understood that any clay is included in this disclosure, We preferto use a magnesium silicate because our experience shows better results with this class than with any other.

From a supply tank 1, through valved line 2, oil is delivered by a pump 2, through valved line 3 into a mlxer 4, in which the proper amount of alkali is thoroughly mixed with the oil. The alkali is introduced under pressure into the mixer 4, through valve contained line 5 from a blow case or pump 6, air being supplied for pressure purposes, where the blow case system is employed, from a suitable source, not shown, through valve controlled line 7, and alkali being furnished throuo'h valved line 8 from a suitable supply vessel 9.

In the mixer 4, referred to, oil and alkali are a itated vigorously to effect as nearly, a's may e, a perfect action of the alkali upon the oil and such action is the more effective where the oil and alkali are broken into minute globules or particles. In this preliminary treatment of the oil, we remove or place in condition for removal, the greatest percentage 'rt' undesirable matters foreign to, or appearing in, the oil as a result 'of refining, or other treatment.

When the oil and alkali have been thoroughly mixed, the mixture is forced through valved line 10 from the top of mixer 4 into a tank 11, to which clay, or other earthy material suit/ed to the purpose, is supplied from a hopper 12, in amounts variably controlled by any well known mechanical agency, as a power feed, shown at 13. We find that the use of about one pound of alkali to thebarrel of oil is approximately the correct proportion to maintain. By means of a pump 14, the mixture of oil and alkali and clay is drawn through valved line 15 from the bottom of the tank 11, and forced through line 16 into line 17. In order to maintain the bodies in a state of agitation and intimately mixed, we may re-circulate the mixture or part of same through the pump 14, which preferably of the centrifugal type. The mixture or portion of same for this purpose, may be diverted from flowing through line 17, and caused to flow through line 16 back to the bottom of the tank 11, this line 16 provided with a valve 16 to control the circulation and agitation of the mixture in the tank 11. A valve 16 on line 16 co-operates with the valve 16 to cause the fiow of the mixture'directly into line 17. This circulation and re-cireulat-ion may occur during and without interfering with the free normal liowv of the mixture through the system, and prevents settling and stratification vof the components of the mixture, in the line 16 and also in the tank 11. Such re-circulatiou also enables the clay the more etliciently to i caused totravel through a heater 18, of any desirable type, and supplied with any coni venient medium of heat. The heater 18 is connected at the bottom to'line 17 through pipe 19, having a valve 19', to control the inflow ofthe mixture to said heater 18, and at the top, the heater is connected to the line 17 through pipe 20. having a valve 20' for governing the outflow of the mixture from the heater backv into the main line 17, a valve 21, being provided on said line 17, and intermediate the pipes 19 and 20 to shut off the flow of the mixture directly through said line 17, when it is desired to by-pass such mixture through the heater 18. We subject the mixture to heat in the heater 18 to effect a greater and more thorough adsorption of the alkali by the clay. While we find, regardless of heavy precipitates of impurities from the mixture, that alkali adsorption of the clay takes place to a greater or lesser extent, depending entirely upon any impairment caused by the coating of the clay particles, we find also that this eurtailment of the adsorpt'ive efficiency of the clay is oli'- set by subjecting the mixture to heat, which causing the mixture to expand, brings the alkali into intimate contact with the clay, with the result that the percentage of adsorption of the clay is as high as is possible to obtain, and equally as high as where the clay and alkali are directlv mixed together. Obviously there will be little or no imped ance of the adsorbing or filtering properties of the clay, where the oil used in conjunction with the alkali, which the clay is to take up, has been priorly alkali treated and the tarry and gummy residues removed therefrom. In that case, the oil is clear and will remain clear, practically throughout the whole process of treating the clay. In any event, heating the mixture is more conducive to a perfect assimilation by the clay of the alkali carried b v the oil, and the temperature which we find mostadvantageous does not exceed 375 F.

In t-he practice of this invention on many oils, we find that a substantially water-dry clay is preferable and yields the best results. This is particularly true with refined hydrocarbons of the lighter gravit-ies. We have discovered, however, that on certain oils, other than the refined hydrocarbons of the lighter gravities, a water-dry clay or-one substantially water-dry, does not work with the satisfaction and efficiency of a clay containing water in determinate quant-ities. This is especially true of lubricating oils, where we have found a water content of ture.

Where the raw clay used is deficient in the amount of water, that deficiene may be supplied either in the form of ree water or water vapor, to the heater 18, through which the mixture of oil, alkali and clay is passing. Water vapor or steam may be supplied to the mixture through line 18 controlled b valve 18; water may be supplied throug line 18 leading from a suitable source, and controllable by a valve 18". Both there fluids, in addition to furnishing the re uired quantity of'kwater, may maintain the mixture in a state lof. agitation within the heater 18, which, while heretofore designated a heater, may have the additional function of a means for mixing the water or water vapor with the clay of the mixture passing therethrough. By means of a valve 18, the heating fluid may be either wholly or partly diverted from the heating coil 18b in the heater 18 to the line 18.

It being understood that the mixture is under a pressure from the pump 14, thefurther progress of the mixture occurs through line 17 which is connected to the top of a settling chamber 22 and through which line 17 the mixture is delivered into this chamber 22` and to one side of a partition 23, vertically suspended therein a determinate above the cone-shaped bottom 24. This chamber 22 is of'a diameter sufficient to cause the velocity of the incoming mixture to drop to a point at which the clay will readily settle out of the oil. The supernatant oil, rising on the other side of the partition 23, however, is forced out of said chamber 22, through line 25 having valve 25 and into line 26, the line 26 being connected to the line 17 and the iiow from said line 17 into line 26 being controlled by valve 26` and the valve 25 on the line 25, serving to control the flow of fiuid from the chamber 22 to the line 26. When by-passing the mixture from line 17 into line 26, the valve 17 is closed; valve 25 on line 25 is closed and valve 26 is opened. The clay which has settled out from the mixture, with the alkali content of the oil adsorbed, passes from the conoidal bottom 24 0f the chamber 22,

through valved line 27 into a centrifuge 28.

To prevent splashing, of the clay, and to increase storage of treated clay and at times to help the operation at the point of delivery into the centrifuge, the clav may be directed to a tank 29, through line 30 having a valve 30. and caused to gravita-te from said t"nk 29 through a pipe 31 having valve 31 at the bottom of tank and leading into the centrifuge 28. .When the clay is diverted int-o the tank 29, the passage of same through the line 27 isprevented by a valve. 27. The clay which has settled in the conoidal bottom of the tank 22 isforced out from said tank under ressure of the pump 14 to the centrifuge, irectllyhor through the circuit )ust described. is settling out in the chamber 22, represents substantially the bulk of the clay contained in the liquid or mixture, the balance which has not collected in the chamber and -which is still in suspension, b emg carried out of said chamber 22, into line 26, for,recovery in another manner, as ex lained presently.

xcept that small percentage of oil which resists mechanical separation from the clay by reason of the intimate union.with it, all oil still contained in the clay when it is dehvered to the centrifuge, is expelled from the clay by centrifugal force, which throws out the liquid from and through the clayey mass and performs, in addition an excellent and thorough filtration. The clay relieved of its oil content, but with its alkali charge undisturbed, is discharged from the centrifuge' through the chute 32 into a bin 33 from which the treated clay is received and apportioned in bags 34 or other convenient receptacles for further use. The liquid or oil which is expelled from the clay passes from the centrifuge 28, through line 35 into a trap 36 in which sedimentary and other foreign matters settle and accumulate, especially should a leak develop in the filter cloth of the centrifuge, and from the trap 36, the oil, cleaned-and ready for use, travels through line 37 to a storage tank 1, this line 37 provided with a valve 37 for controlling the flow therethrough.

As stated above, the supernatant oil, which has Separated out from the clay in the chamber 22, passes out of the chamber through the line 26, into a filter press 40 of known type and construction. and composed of filter leaves suspended within a case. the leaves interposed in the path of flow of the oil and separating by filtration the clay. or clayey material'carried in the oil. After the expression of the clay from the oil by this filtration method, the clay is delivered into a hopper 41, from which it enters preferably a screw conveyor 42, by which the clay is returned to the centrifuge for further treatment for the purpose of extracting from it, to the smallest globules', the oil still contained therein. These small extractions of claysY are likewise in the bin 33 for further distribution. The oil from which the suspended clay bodies or particles have been removed, is carried through the lines 43 and 26 into the storage tank 1, valves 43 and 26" respectively, being provided on said pipes 43 and 26 to control the flow, asappearing presently. The liquid from the chamber 22, however, may be caused to cir-y cumvent the filter press 40, especially Where,

lit() treated is then added to this mixture.

the filter press exists. This diversion of the flow may be effected by closing the valve 40', on t e line 26 leadinfr to the press, clos- "ing the valve 43 on the l1ne 43 leading from the filter press 40; closing a valve 44' Online 44, connecting the line 26 with the initial supply line 3 and opening the valves 39 on line 39 and valve 26 respectively on op osite sides of the connecting line 43. In t 1s wise, the liquid may travel past the filter press. and directly into the receiving or storage tank 1, or under the pressure exerted upon the fluid in the llnes by the pump 14, the fluid, may be forced back into the line 3, and into the mixer 4 for further use in treating other clays. This is effected by opening the valve 39', closing the valve 26 on line 26 and opening the valve 44 on line 44; or by by-passing the fluid through line 26, filter 40 and line 43, leading from the filter 40. The oil may therefore be re-circulated and re-used for treating other clays, so soon as it leaves or separates from the clay in the chamber 22. It may thus enter continuously into the treatment of the clay, or it may be, as stated, delivered to the storage tank 1, from which the cleaned oil may be pumped through the line 3.

In carrying out the process, oil and alkali are mixed in the mixer 4, and the clay tolie Y using an oil as a carrier for the alkali, we are able not only to bring about an intimate contact with hydrosilicates with consequent high adsorption, but in addition, the oil used to treat the hydrosilicates is also treated. By practicing the process in this wise, oils and also the hydrosilicates may be simultaneously treated, thereby avoiding the necessity for separate treatment and special handling of the hydrosilicate, with the high costs incident upon this manner of operat-ion.

We find that many of the hydrosilicates that are used in the treatment of oils, especially. of the hydrocarbon type and class, show an augmented capability for adsorption when heated, whereby hygroscopic water and also constitutional water may be driven off; but that heat must not be great enough to work injury to the iine, minute and delicate, structure of the hydrosilicate, by reason of which its decolorizing power, its filtering quality, and its adsorbing properties ma be destroyed. Such treat-ment by heat of t e hydrosihcate follows the mixing of same with the mixture of alkali and oil. On the other hand, we find, in many cases, that far better results are obtained by not removing the water content of the clay, or at least not below 10%, and that, should the uantity be not present in the clay, we add t e necessary amount in either the form of water-or vapor.

After thoroughly mixing the hydrosilicate, oil and alkali, which mixing is the greater and more intimate in thepresence of heat, the mixture is delivered to a settlingv chamber 22, the bottom of which, constitutconveyed to the centrifuge. The clay or hydrous silicate under centrifugal force expels the maior portion of the oil which the clay has adsorbed. In this centrifuge 28, the speed of which may be regulated to control the amount of oil desired expelled from the clay, the clay may be continuously discharge from the settling chamber, and thecontinuous expulsion of the contained. oil effected. It is found that only such a small amount of oil is retained by the clay as will prevent 'it .from caking or hailing, but the centrifugal force has ractically no eli'ect upon the alkali adsorbed by the clay. In ordinary practice, we find that the amount of oil in the treated clay does not exceed 5%.

The clay removed from the centrifuge is then ready for immediatev use, and its use continued until its power of treatment, whether by reason of exhaustion of the alkali content or by virtue of the loss of its natural adsorptive properties and filtering and bleaching capabilities, has been impaired.V

The oil used in the treatment is returned are to be treated may be added to the treated oil in the vessel 1, or entirely new oil used for the double purpose of treating the oil and treating the clay simultaneously..

What we claim is:

1. The process of preparing an adsorbent for hydrocarbon oils which consists in mixing with petroleum hydrocarbons an alkali dissolved in water ,in vigorously agitating the mixture of petroleum hydrocarbons and dissolved alkali, in mixing clay with the mixture of the dissolved al ali, in separating from the mixture the excess petroleum hydrocarbon, and in then recovering the treated clay.

2. The process of preparing an adsorbent for hydrocarbon oils which consists in mixing with petroleum hydrocarbons an alkali dissolved in water, in agitating the mixture, in then mixing clayV with the mixture of the hydrocarbon oil and alkali, in agitating the mixture, and in then removing the excess etroleum hydrocarbon and hydrocarbon oil and recovering the treated for hydrocarbon oils which consists in mix- `mg an alkali dissolved in water with petroleum hydrocarbon from which impurities have been removed, in agitating the mixture, in then mixing clay with the mixture of petroleum hydrocarbon and alkali, in agitating the mixture in the presence of heat, in expelling the excess petroleum hydro# carbon, and recovering the treated clay. y

4. The process of preparing an adsorbent for oils which consists in mixing an alkali dissolved in Water With puriiied petroleum hydrocarbons, in agitating the mixture, in then adding cla to the mixture of alkali and petroleum ydrocarbons, in agitating the resulting mixture to cause the particlesof clay and dissolved alkali to become coated with films of the hydrocarbon thereby to prevent evaporation of the water from the alkali, in removing the excess etroleum hlydrocarbon, and in recovering t e treated c 5. The process of preparing an alkaline adsorbent for oils, which consists in mixing an alkali dissolved in water with petroleum hydrocarbons from which impurities have been removed, in agitating the mixture, in adding clay to the mixture of alkali and petroleum hyrdocarbons, in agitatin the resulting mixture in the presence 0% heat to cause the granules of clay and dissolved alkali to become coated with lms of the petroleum hydrocarbon and thereby prevent the evaporation of the Water from the alkali, in then removingthe excess petroleum hydroearbon and recovering the treated clay.

6. An adsorbent for oils consisting of clay. rendered alkaline, the clay particles with the alkaline content coated by films of oil.

In testimony whereof we have set our hands.

WIRT D. RIAL. EARLE W. GARD. 

